This SkimStopper product is a credit card size sleeve for protecting 13.56MHz RFID cards against unwanted access. It contains a special protection sheet which blocks RFID signals from reaching the card whilst inserted.

The introduction of contactless (RFID) technology in mainstream applications such as Oyster cards (London Transport) and passports has brought with it increasing concerns about data security. The RFID-Blocking Sleeve provides a cost effective solution to this worry by making it impossible for data to be read from contactless cards operating at 13.56 MHz such as the Oyster card.

This product is also a US Government FIPS-201 approved electromagnetically opaque shield. These risks are considered enough of a threat by the US government that they have instigated the roll out of RFID-Blocking Card Sleeves across their General Services Administration.